The present invention relates to lifting devices and, more particularly, to a quick connect/disconnect tank lifting brace for rapidly lifting and transporting heavy tanks such as used in the oil field environment offshore or onshore.
At times, during drilling operations, drill cuttings and other debris or waste cannot be simply discarded into the water. As a result, during drilling operations efforts are undertaken to discard the drill cuttings and other debris or waste (hereinafter sometimes referred to as xe2x80x9cdrill cuttingsxe2x80x9d).
Depending on the hole size, penetration rate and the depth of the hole, tens to thousands of barrels of drill cuttings are produced. Depending on the size of the tank, a tank may store between 13xc2xd to 25 barrels of drill cuttings. The xe2x80x9creal estatexe2x80x9d in the offshore oil field environment is very limited. Thus, the drill cuttings must be hauled from the offshore platform and discarded onshore. However, there is still the problem of limited real estate that can be used on the offshore platform/rig/dock for storage tanks.
It is estimated that drilling costs approximately $2,000 to $10,000 per hour. Therefore, there are numerous attempts to reduce the duration of the drilling operations even if over time a mere hour is saved. As can be appreciated, offshore platforms or rigs used in deep water drilling are more costly by virtue of their distance from land, depth to the earth""s surface, etc.
Presently, the tanks employed in drilling operations have eyelets or padeyes at the corners of the tanks for coupling the lifting cables to the tank. Coupling the lifting cables to the eyelets (padeyes) or other discretely positioned couplers, affixed to the tank, could be performed rapidly if four laborers were present at each corner to connect and subsequently disconnect the lifting cables from the eyelets (padeyes) or other discretely positioned couplers. As can appreciated, this is prohibitive and a waste of valuable labor.
Most often, one to two men are used to couple a sling to the corner eyelets or padeyes of the tank. The total tank turnaround time to lift, via a crane, and connect the sling to a tank, transport the tank, disconnect the sling and return the sling to the next tank takes approximately fifteen (15) minutes per tank. With current technology, a tank can be filled with 25 barrels of drill cuttings in approximately five (5) minutes. Thus, at times, the drilling operations are limited to the tank turnaround time in which these tanks can be removed and replaced using one (1) crane.
I predict that the turnaround time for the quick connect/disconnect tank lifting brace of the present invention is approximately seven (7) minutes or about one-half the turnaround time of the sling. This is particular advantageous for drilling the top of a wellhole since, at the top of the wellhole, more drill cuttings are generated.
As will be seen more fully below, the present invention is substantially different in structure, methodology and approach from that of prior lifting devices.
The preferred embodiment of the quick connect/disconnect tank lifting brace of the present invention solves the aforementioned problems in a straight forward and simple manner.
Broadly, what is provided is a quick connect/disconnect tank lifting brace for use with a tank with a top lid or cover having an overhang. The tank lifting brace comprises an adjustable crossbar having distal ends and two pivotal end clamps wherein each end clamp is pivotally coupled to a respective one of the distal ends. A pair of clamp pivoting assemblies is included wherein each clamp pivoting assembly pivots a respective one of the pivotal end clamps via a pair of pivot arms. Pivoting is accomplished via a threaded actuating rod parallel to the adjustable crossbar and coupled to the pair of pivoting assemblies wherein rotation of the threaded actuating rod effectuates, in unison, pivoting of each pair of pivot arms via the pivoting assemblies.
In view of the above, an object of the present invention is to provide a quick connect/disconnect tank lifting brace with a pair of clamp pivoting assemblies which are spring biased via a spring biasing force for biasing the end clamps to an open position. Thus, in operation, when the quick connect/disconnect tank lifting brace (without a tank) is being lifted by a crane or hoist via lifting cables, the force exerted by the lifting cables onto the clamp pivoting assemblies does not significantly overpower the spring biasing force and thus leaves the jaws (the end clamps) essentially open and suitable for clutching a tank. In other words, this feature allows the quick connect/disconnect tank lifting brace to remain in an open position which, when transported to the top of a tank, allows such lifting brace to easily be positioned for clamping the tank. Advantageously, when the end clamps are in a closed position, if the end clamps are not locked, the lifting force can automatically lock the end clamps and their pivotal rotation.
The present invention further contemplates a quick connect/disconnect tank lifting brace for use with a tank with a top lid or cover having an overhang comprising a crossbar having distal ends and pivotal end clamps, each end clamp pivotally coupled to a respective one of the distal ends. The brace further includes a pair of clamp pivoting assemblies, each clamp pivoting assembly pivots a respective one of the pivotal end clamps between an open position and a closed position and biases said respective one of the pivotal end clamps to said open position. Furthermore, the brace includes an actuating rod parallel to the adjustable crossbar and coupled to the pair of pivoting assemblies wherein articulation of the actuating rod effectuates, in unison, pivoting of each pair of pivot arms via the pivoting assemblies to a closed position.
The present invention further contemplates a quick connect/disconnect tank lifting brace for use with a tank with a top lid or cover having an overhang comprising a crossbar having distal ends and pivotal end clamps, each end clamp pivotally coupled to a respective one of the distal ends. The brace further includes a pair of clamp pivoting assemblies, each clamp pivoting assembly pushes to pivotally close, via a pushing motion, and, alternately, pulls to pivotally open, via a pulling motion, a respective one of the pivotal end clamps and biases said respective one of the pivotal end clamps to an open position. The motion is carried out using an actuating track mechanism coupled to the adjustable crossbar and coupled to the pair of pivoting assemblies wherein actuation of the actuating track mechanism effectuates, in unison, the pushing motion to pivot the end clamps to a closed position or the pulling motion to pivot the end clamps back to the open position.
Another object of the present invention is to provide a quick connect/disconnect tank lifting brace having end clamps with two end plates fixedly secured in parallel spaced relation via a cross pivoting rod pivotally coupled to the adjustable crossbar. Each end plate comprises a forward portion having formed therein a mouth or an opening; a central portion affixed to the cross pivoting rod; and a rear portion having a hole formed therein for attaching thereto a lifting cable.
The present invention contemplates a pair of end plates which include a central portion having a protruding arc-shaped edge which (1) defines an arc of rotation of the end clamps for rotating the mouth or opening in and out of the open and closed positions; and (2) footing for balancing the quick connect/disconnect tank lifting brace. Moreover, the mouth or opening has a generally squared xe2x80x9cCxe2x80x9d-shaped profile.
It is a still further object of the present invention to provide a quick connect/disconnect tank lifting brace which includes shackles for coupling lifting cables to the end clamps. Thereby, during lifting, the weight of a tank is transferred to the lifting cables to counterbalance the force exerted by the weight of the tank directly applied to the forward portions of the parallel plates.
Additionally, what is provided is a method of lifting of a tank with a quick connect/disconnect tank lifting brace comprising the steps of: positioning the quick connect/disconnect tank lifting brace over a top cover or lid of a tank; applying a pivoting force to effectuate pivoting, in unison, of end clamping members having a mouth so that an overhang of the top cover or lid is received in the mouth; and, lifting the rear-ends of the end clamping members with lifting cables affixed thereto to effectuate a lifting force to an underside of the overhang and providing a counterbalancing moment force to counterbalance the weight of the tank.
A still further object of the present invention is to provide a counterbalancing moment which compensates proportionately for the weight of the tank so that the end clamps in the closed position or the locked position, under the weight of the tank, do not rotate in a direction which would xe2x80x9cspit-outxe2x80x9d or otherwise unclamp or disengage the overhang of the tank.
The present invention further contemplates a method of lifting of a tank with a quick connect/disconnect tank lifting brace having end clamps, each end clamp having a central rotation section with a forward depending mouth and a dependant rear-end, and the tank having sidewalls and a top cover or lid extending beyond the sidewalls to produce an overhang. The method""s second step includes first positioning the quick connect/disconnect tank lifting brace over a top cover or lid of a tank. The second step includes applying a pivoting force to effectuate pivoting, in unison, of the end clamps so that the overhang of the top cover or lid is received in the mouth. The method""s third step includes lifting the rear-ends of the end clamps with lifting cables affixed thereto to effectuate a lifting force to an underside of the overhang and a counterbalancing moment force to counterbalance the weight of the tank.
The method of the present invention contemplate a second step which includes pivoting, in unison, the end clamps until a front surface of each end clamp abuts or is in direct contact with a sidewall of the tank to effectuate locking of the end clamps in a closed position.
The present invention further contemplates a method of lifting of a tank with a quick connect/disconnect tank lifting brace having end clamps, each end clamp having a central rotation section with a forward depending mouth and a dependant rear-end, and the tank having sidewalls and a top cover or lid extending beyond the sidewalls to produce an overhang. The method""s first step includes applying a spring biasing force to the end clamps to maintain the mouth in an open position. The method""s second step includes, during the first step, lifting and maneuvering the quick connect/disconnect tank lifting brace with a lifting force less than the spring biasing force. The lifting force is substantially equal to the weight of the lifting brace. Thus, the heavier the lifting brace, the more the spring biasing force. The method""s third step includes, during the second step, positioning the quick connect/disconnect tank lifting brace over a top cover or lid of a tank. The method""s fourth step includes applying a pivoting force to effectuate pivoting, in unison, of the end clamps so that the overhang of the top cover or lid is received in the mouth. In other words, the jaws (the end clamps) are clamped down. The method""s fifth step includes lifting the rear-ends of the end clamps with lifting cables affixed thereto to effectuate a lifting force to an underside of the overhang and a counterbalancing moment force to counterbalance the weight of the tank.
In view of the above objects, it is a feature of the present invention to provide a quick connect/disconnect tank lifting brace which is relatively simple structurally and thus simple to manufacture, operate and maintain.
Another feature of the present invention is to provide a quick connect/disconnect tank lifting brace which is durable and strong.
A further feature of the present invention is to provide a quick connect/disconnect tank lifting brace which is adapted to save time and cost, associated with oilfield operations, through the reduction in time to accomplish the connection and disconnection of the brace to and from a tank used to discard drill cuttings or other waste and debris.
An advantage of the present invention is the spring biasing of the end clamps to an open position. Thus, when connecting the brace of the present invention, a laborer does not have to waste time opening the end clamps so that they may be subsequently coupled around an overhang of a tank. The spring biasing keeps the end clamps open while the lifting brace is being positioned over the tank and allows the end clamps to be quickly closed.
A further advantage of the present invention is the removal of any play in the pivoting assemblies so that the minimum number of revolutions of the threaded actuating rod is needed for the pivotal rotation of the pivotal end clamps in and out of the closed and open positions.